新型阳离子水凝胶的分步聚合及表征

Synthesis and characterization of a novel cationic hydrogel by two-step polymerization

基于分步聚合的方法,以甲醛、丙酮、二甲胺为原料通过溶液缩聚制备了新型阳离子水凝胶材料.通过改变原料配比和交联剂用量,优化了凝胶合成工艺;通过对基团结构与凝胶特性的表征分析,揭示其合成机理和使用性能.研究结果表明:通过优化合成工艺,可制得综合性能较优的凝胶产品,其阳离子度可达3.59 mmol/g,蒸馏水中溶胀率为49倍.凝胶分子链上含有大量极性亲水基团;在酸性环境下其表面zeta电位可超过+40 m V;在不高于150℃的环境下凝胶具有良好的热稳定性.此外,溶液温度和p H值等环境因素对阳离子水凝胶溶胀率均有较为显著的影响.

In this study,formaldehyde,acetone and dimethylamine were used as raw materials to prepare a novel cationic hydrogel by two-step polymerization. The synthesis process was optimized by changing the ratio of raw materials and the dose of cross-linking agent. Characterization on the functional groups and properties of hydrogel revealed its reaction mechanism and operational performance.Results showed that the cationicity of cationic hydrogel prepared under optimum conditions was 3. 59 mmol / g and the swelling ratio in distilled water was 49. Cationic hydrogel contained large amount of polar hydrophilic groups. The surface zeta-potential could be higher than ＋ 40 m V in acidic solution and good thermo-stability could be observed under 150 ℃. Moreover,environmental factors including solution p H and temperature might exert marked influences on the swelling ratio of hydrogel.